The present invention relates to a tufting machine for tufting a background pile and inserting or overtufting additional pile at predetermined locations to form a pattern in the background pile.
In the tufted carpet industry, there is a demand for machines which are able to produce a carpet of one or more background colors with an intermittent pattern of one or more pattern colors. Such a carpet is conventionally produced in one of two different ways.
The most common process is to bury the color used for the pattern in the parts of the carpet where the pattern is not required. This is done by tufting with the pattern color at the lowest possible pile height in the areas between the pattern. This is reasonably satisfactory for carpets with a high pile height. However, even then, it is difficult to control the yarn feed to produce a single tuft of the pattern, and it is also wasteful of yarn to tuft at a low pile height in areas that will not be seen. However, the real problem with this method is for carpets with a low pile height, for which there is an increasing demand in certain markets, where it becomes impossible to hide the buried color. This technique is therefore not suitable for producing such patterned carpets at low pile heights.
A second technique is known as overtufting. This is simply where the carpet is tufted by a first tufting machine with the background color, and is then fed through a second tufting machine where the pattern is tufted into the carpet, the second machine being a controlled needle individual controlled needle machine. Examples of this process are illustrated in U.S. Pat. Nos. 4,693,190 and 4,726,306. With this method precise control of the positioning of the pattern is impossible preventing a tuft of the pattern from being placed precisely between tufts of the background color. Not only can this affect the aesthetics, but it can also cause tufts of the background color to be punched out, pierced or split as the pattern is created making this method generally unsuitable for loop pile carpets. Additionally, the machines which produce these fabrics are controlled needle cut pile machines, loop pile machines of such type not being known. Also, as passes through two tufting machines are required, this process is slow.